pearl pigment factories

The annual production capacity of high-grade rutile titanium dioxide has reached more than 400,000 tons. It is one of the largest TiO2 manufacturers in China at present. It has more than ten product brands of Taiohua, Jinxing and other brands, and its products are sold in more than 50 countries and regions around the world. It has long maintained the excellent performance of the second overall ranking in the domestic titanium dioxide industry.
This article discusses the discovery of phosphorescent lithopone on watercolor drawings by American artist John La Farge dated between 1890 and 1905 and the history of lithopone in the pigment industry in the late 19th and early 20th centuries. Despite having many desirable qualities for use in white watercolor or oil paints, the development of lithopone as an artists’ pigment was hampered by its tendency to darken in sunlight. Its availability to, and adoption by, artists remain unclear, as colormen's trade catalogs were generally not explicit in describing white pigments as containing lithopone. Further, lithopone may be mistaken for lead white during visual examination and its short-lived phosphorescence can be easily missed by the uninformed observer. Phosphorescent lithopone has been documented on only one other work-to-date: a watercolor by Van Gogh. In addition to the history of lithopone's manufacture, the article details the mechanism for its phosphorescence and its identification aided by Raman spectroscopy and spectrofluorimetry.